Underfed stoker.



W. F. SMITH. UNDBRFBD s'roxn. unicum; FILED nov. 2a, 1910.'

Patented July 4', 1911.

w, s up m T 0 2 VW W/NEssEs {.bottomj of the throat.

TLA further object is-'ifo .oii'nting for each replier@ y fflid' shaft on; which the lrocker 'freely lfrom the side Walls 'ofthe magaii'i'e.

' nnnRRrRDmgsr'oKRR.

speaiajcation ,bf Letters raient.

- f UNITED STATES `ratteuit;orrica1 WALTER RsMITH, o'rjRALTIMo'Rr-i, MARYLAND, assieNbR' To THR- sMoKRLRss sToxRR contraint,- aA CORPORATION ORDRLAWARR. i

i A I y Applicationiiieiiiidvvembera3,i91o.juseria1nofssaos. i

To all whom it may-concern: f i

Be it known `that I',i-\VALTER F.'SMITH,& citizen ot the United Statesf'residingat Baltimore city, Stateof Maryland, hav-ein? vented a certain -newhand useful Underfed.

. Stoker, of which the following-is' afspecification, reference being had therein-to the accompanying drawing. Y

This invention, relates to an underfed stoker for furnaces or thelike of that `type consisting of a sunken magazinextending longitudinally of the gratgeyorhearth and having a plurality-if oscillating conveyers orwoolgcrs that progressively feed .the fuel vWardly from a' front hopper to the rear portion ot' the grate, andat the same time crowd fuel out of the magazine laterally to the grate surfaceor surfaces at one or both sides of the magz'tzine. i

The inventioirhas for-one of its objects to' improve andsimplify the construction and operation of devices of this character so as to be comparatively simple and inexpensive Jto-maiiufacture. and install, thoroughly reliable vand efficient i`n use, andereadily operated.

Another objectof the invention is toim- .prove the arrangement of the -magazine at ythe throat so .that fuel fed from the hopper to the magazine by the initial or starting conveycr 'will readiliv pass from the throat to the first conve'yer without thett'uel jamming in front oit the latter, the first conveyer beingy mounted 'under the .plane of the Another object o'lf the invent'oln' is thc-priovision of a plurality ot conieyers or rockers -having a novel. operating mechanism consist- .A ing ,of an eccentric,v levers Aind links soar ranged ..that alternate el; lor conveyeis move simultaneously pp `ite i. directions'J th'ere-beingp'italesf or`. 'n'clin'e'd'- planes bietween. "adjacent rochers so thatv the `fuel will be progressively elfe'vfate'd Wh-ile'itis progressively moved backivrdlyg A' iilttiid@ liail raie fomi- Of a siiving's,l the shaft litsgei'fds' xediii' bearingsy of novel construction depending' lAnother ob"ect 's.the employment of rockng'grate bars whi'fchjafre' connected'together Patented-fairly 4, 1.911;

fofsynchronous movement in the same d irec- A tion f and' 'ope'ratii-'ely related to` 'an eccentric oir the" 'same-:Shaftr the' eccentrieriox the, `conveyersor rockers in the magazine.

' v "VVith' theseffobject's --in jview and others, as

willappe'ar as the'v description proceeds, thev invent-ion comprises .the-various novel features'of construction' and arrangement 'of' parts which Willbe more fully described .hereinafter and set forth with particiilarity in the claims appended hereto.

In the accompanying drawings, which illustrate one embodiment of the invention,`

Figure 1 is` a side 'View voli-the fuel-feeding magazine. Fig. 2' 1s a transverse section on line 2-2, Fig. l, and Vdrawn on an enlarged scale. F ig. central longitudinal section of the magazine.- Fig. 4 is aV bottom plan view of the maga-zine. Fig-5 is a detail=view of the bearing for one of the con- Similar reference characters are employed to designate. corresponding parts throughout f the Views. A

. .i Referring to the drawings, A designates atrough-like magazine which 'entendslongitudinally of a `furnace or other grate or' 'tlanges 2 that. are provided on their top surfv faces with semi-cylindrical bearings or seats I for ineen-ing the journals l ot' rocking',

grate bars .soA that' tlie' ariangeinent, as

shownrlearly in Fig. 2 is such that the" magaziie islsunken below the surface ofthel gratebed. t At. the front of the'inagaziiie 1S Wall '(n'ot slioivnllfof',tlie'iurnace Iandreexterior to, the' 'urnacerf" :B'etiveeln thethroatI --6A and rear` end of'tlie magazine' are ,spaced ioo upper ends` disposed :it/successively higher levels beginning -that uptalie, nearest i" the rfront. 'lhese' uptak'es clonsvtitiite" or-- tions of the bottom of 'the magazine, fan between iac ljacent' uptakes'b'and also between the frontl lptakeand throat are openingsiQ in 'the bottom fthe magaziiie for accommo- "datin tlie oscillating ,conveyer s or rockers A1'0 an -'-11 'tli'e1rocl zers. 11 being' arranged a1- ternat'ely mr-...respectif to the' rockers 10.

iden' 12 .on' A I which fuel. lodges vso as to be jpiiishedf up A adjacenttheu take '.as the rocker or .conveyer is oscillate 'The shoul' de'r'12 is rthelradial,faceof the sector portion each'coiiveyei and extends 'from' the arcuatelfa'cejof the' sector ortion to the hub of the 'uptakes and rear edge of the bottom plate'of the throat so that the'coal is scraped oft' the said surfaces during the downward vmovement of thel conveyers to coal-receiving position; 'It will thus be seen that the conveyersv 4are constantly kept clean so that .there is no dangerv of their becoming jammed and stopping the mechanism. lt is lalso to be noted that the conveyers are located wholly behind the bottom plate of the throat and behind the uptakes so that they are' in 4the best position to receive fuel as it is moved rearwardlyV by. the alternate rocking of the two sets of alternately arranged.

conveyers, and as the uptakes have their rear ends elevated successively from the front ,to the rear, the fuel feeds laterally out of the magazine simultaneously with .the

rear movement of the fuel;

The shafts 13 on w 'ch the conveyers freely oscillateare located elow the bottom so'with reference tothe rst rocker 10, an d the shoulder 12 of this rocker is disposed A' 'plate 14 of the throat. This is particularly belowthe bottom 14 of the throat so that fuel will drop from -the'latter upon the shoulder 12 on the first rocker or conveyeif; :with theresult that jamming of fuel in thel throat-will be prevented, as would be the case if the firstV rocker occupied an elevatedposition.

Immediately under the hopper 7 and at the lfront end of the' throatY is an. oscillatory conveyer oi' rocker 15 that acts asa'starter l'r-iconveyer operates as aout-off valve to prefor' "'i novifng the fuellongitudinally of the magazine, and 'this conveyer oscillates backb andforth' in an opening 16 atgt-he'frontl of the`V magazine and hasa shoulder 17 v'be-I hindwhicli the fuel dropsfrom the hopper when the starting conveyer is swung forwardly. The surface 18 of'this starting "the throat 'of the magazine. with the present .device than 'with those stokers in which-the ventl .fuel fromjpassing into the magazine during the rearward swinging movement of the conveyer.A lVhen the conveyer'15 is in its forward' fuelreceiving position, the shoulder 17 is approximately on a line with the front Wall of the magazine andthe fuel from the hopper drops behind' the shoulder 17 with the 'result that when the conveyer or rocker swings rearwardly, the body of fuel iii the throat of-the magazine is moved horizontally and thefconveyer has no lifting effect whatever on the fuel in the hop# per. Thus, consideiiably less power' is required 'to force the fuelbackwardly through rocking conveyer` at .the inlet df the throat is horizontal when in receiving position, from which it swin s upwardly and rear wardly. toforce the uel through the throat.

ing the fuel rearwardly through the throat,' the foremost-conveyer 10 is swinging downwardly and hence offers no material resistance to the rearwardly-moving fuel, and as the surface 12 ofA the"conveyer 10 falls considerably below the bottom of the throat, the fuel drops oil' the bottom'of the throat and on the conveyer 10. At the end of this feeding movement of. the fuel under the conveyer-l, the latter is swung -forwardlyto permit another charge of fuel .to pass into the'throat,.'and. at the same time the 'fuel supported on the conveyer 10 is elevated and moved rearwardly on the first up- 100 take 8, thefuel in the throat remaining, for the time being', stationary. By this alter' nate action of the "conveyei's, there is no compression of the fuel in the throat and as the result, the throat is constantly kept 105 clear. it is extremely important that at no point,

Where soft coal is used as' a fuel,

and especially attire throat of the magazine,

should the" fuel besubjectedto compression, because the maga-zine becomes clogged and 4110 the fuel has to e cut away by the use of a chisel and hammer, the furnace being, of

course, rst'shut. down. The shafts 13 of4 the conveyers extend.

transversely under the magazine and ai'e' -.1,l5l`

held rigidly in, fixed, position while the Arockers oscillate thereon. 0n the sidewalls ofthe .magazine are dependin bearings 19 which may be cast integral withA the magazine or otherwise attached, and each. bear- 120 ing, as shown in Fig.- 5, has an openin' 20 of'larger diameter th'antlie end of the s aft l'that enters 'thel same. The opening 20 of the bearing is provided with *inwardlyeiitending lugs 21j that are arranged-on the 125 f opposite side of a vertical-planeand below 'aV horizontal plane passing through 'thecenter'of the bearing, and these lugs have inner arcuate surfaces 22'concentric with the center of thebearingso, that the shaft-'13.will 130 lVhile the front rocking conveyerl is forelit snuglyjon these lugs. lIn the top of each '1- -bearing 19is` a vertically-disposed set .screw v23 Which 'screws down on the top o f the shaft 13 vfor Jamming. the'latter firmly on na'lly from their bearings 'androckers In thls'manner, the rockers or conveyers can be easily-renewed when occasion requires'.-

.Each .rocker or conveyer has a depending arm 24, and these arms are connected with nism comprises a rotary shaft 25 disposeda mechanism forI transmitting oscillatory movement tothe conveyers. This mechain bearings`26 at Athe front of the furnace and on the'shaft is an eccentric 27 which imparts movement to a strap 28 surrounding the eccentric, said strap having an arm 29 which is opera-tively connected Wit-h oppositely-disposed bell `crank levers-'30 andl 3l.' -These levers are provided with short arms 32 that are connected With the arm 29 -by a pin 33 so that the levers `will oscillate as the'leccentric rotates. The levers, whichV swing on shafts 34 mounted in the-bearings 27,'have downwardly-'extending arms, the front lever 31 having two downwardly-ex- ,tending arms a and b, While the other lever ,30 has one downwardly-extending a'rm c.

- 'Ihe arm c of the-lever 30 is connected `by a x -pitman 35 with the arm 24 of the first rocker l10, and a connecting rod 37 lconnects this rocker with the other-rocker or rockers 10, so that all such rockers will oscillate simultaneously. The arm a ofthe lever 31 is connected by a pitman 38 to the arm 24 of the first rocker 11, and the arms of all the rockers 11 are united by va connecting rod 39. The other arm b of the lever 31 is connected by a pitman 40 With the arm 41 of the starting or feeding rocker 15 so ,that this rocker will move on its feeding movement to feed fuel rearwardly through the throat at the same time the rockers l1 move onI their feeding strokes or swing upwardly. Since the levers 30 and 31 are oppositely disposed 'and connected With a common eccentric, it

is obvious that one set of rockers l0 -will swing'simultaneously 1n the opposite 4direction to the other set of rockers 11, so that at a plurality of points along the magaaine the fuel will be receiving a rearward impulse by one set of rockers While the other set are recovering-.or moving to a position to permit fuel to -feed upon them preparatoryto the next impulse, and simultaneously with this action the fuel is conducted through the throat from the hopper by the front or starting rocker l5. I

Itwill be noted.that the operatmg connections between the various rockers and eccentric mechanism are. locateddirectly linder the magazine and Within planes` coin- `connection with. the accompanying drawcident With'the side Walls of the hopper, so

that these operating connections Will be protected from ashes, cinders and dust.

As shoWn'inF ig. 1, the grate bars 5 are provided Withl arms 39 and are connected 70 l'together by a rod'40, and this rod is in are shown .and their eccentrics 44 are arranged one hundred and eighty degrees apart so that the grate bars of one group Will rock in the opposite direction to those of the other group. By this continuous rocking of the" grate bars, the fire Will'be kept clean While the automatic stolzing Igoes on.

From the foregoing description, taken in ings, the advantages of the construction and of the method of operation will be readily apparent to those skilled in the art to which the invention appertains,'and -while I have describedthe principle of operation. of the invention, 'togetheravith the apparatus Which I now `consider to jbe the best embodiment thereof, I desire to have it understood that the apparatus shown is merely illustrative,.- and that such changes may be made when vdesired as are within the scope o f the claims appended hereto.

Having thus described the invention, What I claim as new, is

1.l An automatic stoker comprising a magazine having a throat, a laterally movable conveyer at the front end of the throat for forcing fuel rearwardly therethrough, a. hopper located to deliver fuel behind the l conveyer when the latter is in its forward 110 position, a second conveyer located-.at the rear portion of the throat and having a fuel feeding portion movable to a receiving position below the bottom of the throat, a flathorizontal stationary plate forming the bottom of the throat between the said conveyers, and a mechanism for moving the conveyers simultaneously in opposite directions. Y

2. 'An automatic Stoker comprisinga magazine having a throat, a rocking conveyer at the front end of the throat having an upwardly-extending shoulder movable back and forthl across a vertical line passing throughV the axis of the conveyer to force fuel longitudinally ofgthe throat, a hopper for delivering fuel behind the shoulder, a flatplate forming behind the conveyer the bottom of the throat, 'a rocking conveyer mounted at the rear edge of the bottom plate of the throat and having a shoulder-movable upwardly and rearwardly from fuel-receiving position below to a point above the bottom plate of the throat, and means for movvthe front end of the throat having an upwardly-extending shoulder movable back and forth across a vertical line passing through the axis of the conveyer to force fuel longitudinally of the throat, a hopper for delivering fuel behind the shoulder, a flat plate forming behind the conveyer the bottom of the throat, a rocking conveyer lnounted at the rear edge of the bottom plate of the throat a'nd'having a shoulder movable upwardly and rearwardly from fuel-receiving position below to a point above the bottom plate, arms on the rockers, links connected with the arms, and means for moving the links simultaneously in opposite directions.

4. The combination of an automatic Stoker, with grates disposed laterally thereof to receive fuel, sit-iii st'oker comprising a magazine having a throat at its receiving end, a hopper fromk which fuel descends into the throat, a rocking conveyer disposed at the front end of the throat and having an approximately radial fuel forcing shoulder movable through an angle intersected by a' vertical line from fuel receiving position in line with the front wall of the throat to a position wholly under the hopper to cut oft' the descent of fuel therefrom, a flat plate forming behind the conveyer the bottonia rof the throat, a second conveyer` arranged wholly behind'the rear edge of the said plate and having a fuel forcing shoulder movable from fuel-receiving position below the plate to a position above the same for forcing rearwardly the fuel received from the throat, and a mechanism for simultaneously moving one conveyer to fuel-receiving' position while the other is moving on its feeding stroke.

5. The combination of an automatic Stoker, with grates disposed laterally thereof to receive fuel, said Stoker comprising a 5Q\ magazine having a throat at its receiving end, a lhopper from which fuel descends into the throat a rocking conveyer disposed at the front end of the throat and having an approximately radial fuel forcing shoulder movable through an angle intersected by a vertical line from fuel receiving position in line with the front wall of the throat to a position wholly under the hopper to cut olf the descent of fuel therefrom, a flat plate forming behind the conveyer the bottom of the throat, a second conveyer arranged wholly behind the rear edge ofthe said plate and having a fuel forcing shoulder movable from fuel-receiving position below the plate to a position above the same for forcing rearwardly the fuel received from the throat, a mechanism for simultaneously y moving one conveyer to fuel-receiving position whlle the other is moving on lts feedling stroke, and an uptake in the magazine behind the conveyer, the axis of the second conveyer being disposed below and approximately vertically in line with the front lower edge of the uptake.

6. An automatic Stoker comprising a magazine having spaced walls, uptakes ex'- tending between the walls and spaced longitudinally in the magazine, rocking 'conveyers movable between the uptakes andeach conveyer having a sector-shapedl portion arranged with its curved surface-iin proximity to the rear surface of the preceding uptake 

